Leptospira bacteria, illustration

Caption: Leptospira bacteria, computer illustration. Leptospira is one of a group of helical bacteria known as spirochaetes, which contains many serious pathogens. Leptospira cells have many small coils and an overall C-or S-shaped form. One or both ends of Leptospira are usually hooked. The parasitic species L. icterohaemorrhagiae is the main causative agent of leptospirosis (Weil's disease), but many other Leptospira species cause similar symptoms, attacking the liver (jaundice) or the meninges of the brain (meningitis). Infection occurs through contact with rodents, dogs and farm animals, so farmers, sewage workers and veterinary surgeons are particularly susceptible. Treatment is with penicillin.